Effect of Cardiac Rehabilitation on Cardiovascular Events after Coronary Artery Bypass Grafting in a 6-Year Follow-Up Study

Background: Exercise-based CR is a crucial part of secondary prevention for patients after coronary artery bypass grafting. Yet little is known about the dose– response relationship.Design: Retrospective cohort studyMethods: We used data from the Cheng Hsin General Hospital (CHGH) database to identify patients who had undergone CABG between January and December 2008. 261 patients (102 in the CRG and 159 in the NCRG) were evaluated. We investigated whether a dose–response relationship existed among CR attendance, exercise intensity progress proportion (EIPP), and the short-term event-free rate. For the CRG, the CR attendance was classified into 2 categories of ≥ 6 and u003c 6 sessions; EIPP was derived from intensity difference ratio between the first and last training session, and classified in to 2 categories of ≥ 12% and u003c 12%. The outcome in the 6-year follow-up was the events free rate of cardiovascular events.Results: The event-free survival rate was 59.8% for the CRG and 42.8% for the NCRG. The event-free survival rate was 57.8% in patients who attended ≥ 6 sessions and 61.4% in patients who attended u003c 6 sessions. The eventfree rate between EIPP ≥ 12% and u003c 12% were 66.7% versus and 60.5% (HR: 0.601 vs. 0.482, 95% CI: 0.243– 0.956 vs. 0.358–1.008).Conclusions: CR is associated with more favorable outcomes in CAD patients.CR attendance and EIPP ≥ 12% are associated with higher event free survival rate. Our results support national policy that CR is recommended for CABG, and recommended exercise dose for clinical prescription.